Electric switch.



R. P. BROWN.

ELECTRIC SWITCH.

APPLICATION FILED 0GT.17, 1911.

r 1,018,618, Patented Feb. 27, 1912.

4 1! 315 f 24/ w n we? a I INVENTOR @111 W fl w1rmsssss fi ATTQRNEVUNITED sTAT s EN OFFICE.

RICHARD r. BROWN, or PHILADELPHIA, PENNSYLVANIA.

ELECTRIC SWITCH.

Specification of Letters Patent.

Application filed October 17, 1911. Serial No. 655,138,

To all whom it may concern:

Be it known that I, RICHARD P. BROWN, a citizen of the United States,and a resident of the city and county of vPhiladelphia, State ofPennsylvania, have invented certain new and useful Improvements inElectric Switches, of which the following is a grip or handle by meansof which the operator can throw the switch as desired from without, andthe object of my invention is to furnish a means whereby the contacts ofsaid switch may'beadjusted quickly and conveniently without it beingnecessary to open the case for this purpose.

-My invention is illustrated in the accompanying drawings in which:

Figure 1, is a plan view of an electric switch embodying myimprovements; Fig. 2, a section of Fig. 1 on line wzv.

1 is a plate of slate or some other nonconducting material which carriesthe contacts 23.

4 is a post carried by plate 1 the upper end 5 of which is threaded.

6 is a contact plate secured to plate v1 and surrounding-post 4. 7 acontact plate resting upon plate 6. 8 a sleeve which surrounds post 4and which carries an insulated operating piece or handle 9 and which ispreferably but not necessarily integral with plate 7. Secured to thecontact plate 7 is an arm 10 which is adapted when the plate 7 is turnedabout the post {i to make an electrical contact with any one of thecontacts 2-3, &c., carried by plate 1.

Surrounding the post 4 and bearing against the top of plate 7 is aspiral spring,

11 the upper end of which; bears against a washer 12 which surrounds thethreaded end of the post.

13 are nuts by means of which the washers 12 may be caused to forcespring 11 against plate 7 with varying degrees of pressure.

14 is the top of the case which incloses the contact joints and parts ofthe mechanisnr connected with them. This top is frequently made of glassand is furnished with a perforat-ion 15 for the passage of the sleeve 8a felt Washer 16, or other suitable means, is

employed to make a dust tightjoint at the perforation 15.

In switches for electrical currents of very. low voltage it is essentialthat the contacts be always as near perfect as possible and to this endthey need frequent adjusting. And when the working parts are inclosed ina dust-proof case this latter, unless some provision-be made for makingthe adjustment from without, 'has to be frequently opened causing inmany instances disarrangement of the connected mechanism.- Theconnection between the contacts 2-3,,

&c., and the arm 10 is usually of the knife switch variety and is to acertain extent, self adjusting and self'cleaning. The contact betweenthe stationary plate 6 and the movable plate 7 is the one that requiresmost frequent adjustment and I can accomplish this from without the caseby simply setting the nuts 13 up or down on the screw threaded end 5 ofthe post 4 thus decreasing or increasing the tension of the spring 11and the frictional contact between plates 6 and 7 and at the same timecausing less or more pressure of the arm 10, or the contact piece 17carried by this arm against the contacts 2-3, &c.

Having thus described my invention I claim as new and desire to secureby Let- Patented Feb. 27, 1912.

the tension of said spring may be regulated, a sleeve carried by saidmovable plate surrounding said spring, an operating piece carried bysald s eeve, and a contact arm earned by sald movable plate.

2. In, an electric switch, in combination,

a case one side of which is furnished with a perforation, a stationarycontact plate and a movable contact plate and arm within said ease, asleeve connectedto the movable plate and passing through the perforationin saidfcase; an operating piece carried by the outer endof'said sleeve,:1 post in said '5 sleeve-the lower end of which is secured v to thecase and the upper end of which is threaded,f a nut carried by saidpost, and a coil spring surrounding said post one end of which bearsagainst the top of said movable plate and the other against said nut.

' RICHARD P. BROWN. Witnesses:

GEORGE'W. W. COnNMAN, J. D. ANDREWS.

